The more you know, the more you can imagine. The more you imagine, the more you can know.
The first step in liquidating a people is to erase its memory. Destroy its books, its culture, its history. Then have somebody write new books, manufacture a new culture, invent a new history. Before long the nation will begin to forget what it is and what it was.
You can fool all the people some of the time, some of the people all the time, but you cannot fool all the people all the time.